In X-ray image acquisition technology, an object to be examined is situated between an X-ray source and an X-ray detector. A fan- or cone-beam is generated by the X-ray source, possibly employing collimation elements, in the direction of the X-ray detector. The object to be examined is spatially attenuating the X-ray beam depending on its inner structure. The spatially attenuated X-radiation is subsequently arriving at the X-ray detector, with the intensity distribution of the X-radiation being determined and subsequently converted to electrical signals for further processing and display of an X-ray image. Both the X-ray generating device and the X-ray detector may be mounted on a gantry for rotation around the object to be examined. By providing an according rotation with subsequent acquisition of different X-ray images of varying alignment and orientation with respect to the object to be examined, a three-dimensional reconstruction of the objects inner morphology may be obtained.
In addition to such X-ray transmission imaging, a phase-contrast imaging may determine a phase-shift of the transmitted X-rays and a scattering power of a sample. This provides additional information that may be employed for contrast enhancement, determining material composition and reducing X-radiation dosage. WO 2013/004574 (A1) thereto discloses an X-ray imaging system for phase-contrast imaging comprising an X-ray source, a phase grating, an analyzer grating and an X-ray detector element. An object to be imagined is arrangeable between the X-ray source and the X-ray detector element. The phase grating as well as the analyzer grating is arrangeable between the X-ray source and the X-ray detector element. The X-ray source, the phase grating, the analyzer grating and the X-ray detector are operatively coupled for acquisition of a phase-contrast image of the object.
Carolina Arboleda et al, “Tilted-grating approach for scanning mode X-ray phase contrast imaging”, Optics express, vol. 22, no. 13, page 15447, discloses employing titled gratings for a scanning phase contrast imaging system.
WO 2013/126296 discloses a scanning phase contrast imaging system.